SafariWeb browser · Apple
CVE-2011-3242
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe Private Browsing feature in Apple Safari before 5.1.1 on Mac OS X does not properly recognize the Always value of the Block Cookies setting, which makes it easier for remote web servers to track users via a cookie.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Private Browsing feature in Apple Safari before 5.1.1 failed to properly honor the 'Block Cookies: Always' preference, allowing cookies to be set and persisted even when users had configured maximum cookie blocking. This undermined the privacy expectations of Private Browsing mode by enabling cookie-based tracking despite the user's explicit privacy settings.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
SafariWeb browser
all versions<= 5.1= 1.0= 1.0.0= 1.0.0b1= 1.0.0b2= 1.0.1= 1.0.2= 1.0.3= 1.0b1= 1.1= 1.1.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- None
- Availability
- None
AV:N/AC:L/Au:N/C:P/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Check installed Safari versionOpen Safari, then go to Safari menu > About Safari (on Mac) or Help > About Safari (on Windows). Note the version number displayed.Affected if The version shown is 5.1 or earlier (any version <= 5.1), including any of the specific beta versions listed in the affected products.
-
Confirm Private Browsing usageIdentify whether Private Browsing mode is being used in the browser. In Safari, Private Browsing is activated via File > New Private Window or Cmd+Shift+N.Affected if Private Browsing mode is active or regularly used in the browser environment.
-
Verify cookie blocking preferenceCheck the Safari cookie blocking setting by going to Safari > Preferences > Privacy > Block Cookies. Confirm it is set to 'Always'.Affected if The 'Block Cookies' preference is configured to 'Always' (the most restrictive setting).
-
Test for cookie persistence in Private BrowsingEnable Private Browsing mode with Block Cookies set to Always, then visit a website that sets cookies. Inspect the browser's cookie storage (via Develop > Show Cookies, or check the Cookies.sqlite database in ~/Library/Cookies on Mac) to verify if cookies were stored despite the setting.Affected if Cookies are found to be set and persisted even though Private Browsing is active AND Block Cookies is set to Always.
A user is affected if running Safari version 5.1 or earlier while using Private Browsing mode with the 'Block Cookies: Always' preference, and cookies are still being stored despite this configuration.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate Safari to version 5.1.1 or later on Mac OS X systems to resolve the cookie blocking inconsistency in Private Browsing mode.
Fix this in Safari
Scoped from the published advisory
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-3242 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2011-3242 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data